Bed Flinger: Slower Y-movement as function of Z
(I apologize in advance if this is wrong place for feature request.)
Feature Request: Automatically decrease speed of Y moves by a selectable factor, as height of the print increases. This might improve adhesion and accuracy of tall prints on large bed-flinger printers.
My print volume is 300x300x400. Every small wobble or vibration of the bed (which can never be completely eliminated mechanically) is exaggerated at the top of a tall model. Additionally, depending on the geometry of the model, the model itself can resonate at the top like a tuning fork. Effect can intensify when there is a large mass of filament (say 1kg) already printed below below the current layer, which has a lot of momentum. The result is slighly misaligned layers on tall models, and even scraping of the nozzle on the top of the model during moves. (All of my printers are dual-Z and carefully calibrated.)
This can be worked around by slowing the overall speed of bed movement. But it would save printing time if the slowing could be introduced gradually, as the print gets taller, where the problem becomes more acute.
RE: Bed Flinger: Slower Y-movement as function of Z
The proper place to make feature requests and issues is the Prusa Slicer github repository. That is located here https://github.com/prusa3d/PrusaSlicer/issues
While I don't know an easy way of slowing down just Y you can slow down the overall speed of a print with gcode commands. M220 S100 for example sets the machine to use 100% speed (at least for Marlin based printers like the Mk3 range). M220 S50 makes it print at 50% speed etc. Its similar to what happens when you use the LCD to reduce or increase printing speed.
Given that it can be done via gcode it can also be added to a printers settings to apply it to all models sliced with that printer. If (while in expert mode) you navigate to the Printer Settings>Custom G-code>Before Layer change gcode field you might see something like
;BEFORE_LAYER_CHANGE
G92 E0.0
;[layer_z]
already in there. If you add after that
{if layer_z <= 10}M220 S100
{elsif layer_z <= 20}M220 S90
{elsif layer_z <= 30}M220 S80
{elsif layer_z <= 40}M220 S70
{elsif layer_z <= 50}M220 S60
{elsif layer_z <= 60}M220 S50
{elsif layer_z <= 70}M220 S40
{elsif layer_z <= 80}M220 S30
{elsif layer_z <= 90}M220 S20
{elsif layer_z <= 100}M220 S10
{endif}
You will get a graded slowdown. Of course you would need to decide at what layers and what speed percentages you actually require, the previous is only an example. You add that to the printer profile and then save as a new modified profile. If you then use the 'new' printer profile then anything sliced with that profile will have those same speed changes added to the gcode produced.
the print preview of PS 2.5.2 doesn't seem to take the custom gcode into account but your printer should. Prusa Slicer 2.6 however does display the speed differences so looks like the preview issues has already been fixed in the alpha code.
RE: Bed Flinger: Slower Y-movement as function of Z
Thank you!